Digestive System Quiz

Which enzyme is responsible for beginning protein digestion in the stomach?

• Amylase

• Pepsin

• Lipase

• Trypsin

Answer explanation

Pepsin is the enzyme that initiates protein digestion in the stomach. It breaks down proteins into smaller peptides, making it essential for the digestive process, unlike amylase (carbohydrates), lipase (fats), or trypsin (small intestine).

Which of the following is NOT a function of the stomach?

• Temporarily stores food

• Secretes hydrochloric acid

• Absorbs nutrients

• Secretes pepsin

Answer explanation

The stomach temporarily stores food, secretes hydrochloric acid, and pepsin, but it does not absorb nutrients. Nutrient absorption primarily occurs in the small intestine.

Where is the epiglottis located?

• At the entrance of the esophagus

• At the entrance of the trachea

• Between the stomach and small intestine

• Between the small and large intestines

Answer explanation

The epiglottis is located at the entrance of the trachea. It acts as a flap that prevents food from entering the airway during swallowing, ensuring that air goes into the trachea and food into the esophagus.

What is the primary function of the stomach in digestion?

• To absorb nutrients

• To store bile

• To break down food using acid and enzymes

• To transport food to the small intestine

Answer explanation

The primary function of the stomach in digestion is to break down food using acid and enzymes. This process prepares the food for further digestion and nutrient absorption in the small intestine.

Where is the pyloric sphincter located?

• Between the esophagus and the stomach

• Between the stomach and the small intestine

• Between the small intestine and the large intestine

• Between the mouth and the esophagus

Answer explanation

The pyloric sphincter is located between the stomach and the small intestine. It regulates the passage of partially digested food from the stomach into the small intestine.

What would happen if the pyloric sphincter did not function properly?

• Food would not enter the stomach

• Chyme would not be released properly from the stomach

• Bile would not be produced

• Nutrients would not be absorbed

Answer explanation

If the pyloric sphincter does not function properly, chyme cannot be released from the stomach into the small intestine, leading to digestive issues. This makes 'Chyme would not be released properly from the stomach' the correct answer.

What is the primary function of the duodenum?

• Absorption of water

• Chemical digestion of nutrients

• Storage of bile

• Production of insulin

Answer explanation

The primary function of the duodenum is the chemical digestion of nutrients. It receives chyme from the stomach and enzymes from the pancreas and bile from the liver, facilitating the breakdown of food components.

What role does hydrochloric acid play in the stomach?

• Neutralizes stomach pH

• Activates pepsinogen to pepsin

• Absorbs nutrients

• Produces bile

Answer explanation

Hydrochloric acid in the stomach primarily activates pepsinogen to pepsin, an essential enzyme for protein digestion. It does not neutralize pH, absorb nutrients, or produce bile.

Which part of the digestive system is primarily responsible for nutrient absorption?

• Stomach

• Small intestine

• Large intestine

• Esophagus

Answer explanation

The small intestine is primarily responsible for nutrient absorption. It has a large surface area due to villi and microvilli, which facilitate the absorption of nutrients from digested food, unlike the stomach, large intestine, or esophagus.

What is the function of bile in digestion?

• Breaks down carbohydrates

• Emulsifies fats

• Neutralizes stomach acid

• Absorbs proteins

Answer explanation

Bile emulsifies fats, breaking them into smaller droplets, which increases the surface area for digestive enzymes to act on. This process is essential for the efficient digestion and absorption of dietary fats.